Higher-order Ambisonics (HOA) is a representation of spatial sound fields that facilitates capturing, manipulating, recording, transmission and playback of complex audio scenes with superior spatial resolution, both in 2D and 3D. The sound field is approximated at and around a reference point in space by a Fourier-Bessel series.
There exist only a limited number of techniques for manipulating the spatial arrangement of an audio scene captured with HOA techniques. In principle, there are two ways:    A) Decomposing the audio scene into separate sound objects and associated position information, e.g. via DirAC, and composing a new scene with manipulated position parameters. The disadvantage is that sophisticated and error-prone scene decomposition is mandatory.    B) The content of the HOA representation can be modified via linear transformation of HOA vectors. Here, only rotation, mirroring, and emphasis of front/back directions have been proposed. All of these known, transformation-based modification techniques keep fixed the relative positioning of objects within a scene.
For manipulating or modifying a scene's contents, space warping has been proposed, including rotation and mirroring of HOA sound fields, and modifying the dominance of specific directions:    G. J. Barton, M. A. Gerzon, “Ambisonic Decoders for HDTV”, AES Convention, 1992;    J. Daniel, “Représentation de champs acoustiques, application à la transmission et à la reproduction de scènes sonores complexes dans un contexte multimédia”, PhD thesis, Université de Paris 6, 2001, Paris, France;    M. Chapman, Ph. Cotterell, “Towards a Comprehensive Account of Valid Ambisonic Transformations”, Ambisonics Symposium, 2009, Graz, Austria.